Experimental evaluation of pressure drop in round tubes provided with physically separated, multiple, short-length twisted tapes

Abstract Isothermal pressure drop tests were performed on horizontal round tubes each containing identical, physically separated, equally spaced, short-length twisted tapes (TTs). The tests investigated the dependence of the Darcy friction factor, f , on the empty tube Reynolds number Re , TT twist ratio y , and TT spacing s . The variation of f across TTs belonging to the same test section was also examined. Ranges of the experimental variables examined were: 10,000 ⩽  Re  ⩽ 90,000, 1.5 ⩽  y  ⩽ 6, and s  = 30, 40 and 50. The number of 360° revolutions was held constant for all the tapes and equal to 1.5. Tap water at room temperature and nearly atmospheric pressure was used as the working fluid. A correlation for the Darcy friction factor, in the form f  =  f ( Re , y , s ), was developed from the collected experimental data, with excellent accuracy.

[1]  W. J. King,et al.  III—Relationship between Heat Transfer and Pressure Drop1 , 1931 .

[2]  Sujoy Kumar Saha,et al.  Thermohydraulic Study of Laminar Swirl Flow Through a Circular Tube Fitted With Twisted Tapes , 2001 .

[3]  S. Suresh,et al.  Experimental studies on heat transfer and friction factor characteristics of turbulent flow through a circular tube fitted with regularly spaced helical screw-tape inserts , 2007 .

[4]  Pongjet Promvonge,et al.  Enhancement of heat transfer in a tube with regularly-spaced helical tape swirl generators , 2005 .

[5]  F. Landis,et al.  Friction and Forced Convection Heat-Transfer Characteristics in Tubes With Twisted Tape Swirl Generators , 1964 .

[6]  A. H. Algifri,et al.  Prediction of the heat transfer for decaying turbulent swirl flow in a tube , 1985 .

[7]  W. J. Marner,et al.  On the Presentation of Performance Data for Enhanced Tubes Used in Shell-and-Tube Heat Exchangers , 1983 .

[8]  Pongjet Promvonge,et al.  Experimental investigation of heat transfer and flow friction in a circular tube fitted with regularly spaced twisted tape elements , 2006 .

[9]  Heat transfer and pressure drop in tubes with short turbulators , 1996 .

[10]  Animesh Dutta,et al.  Friction and heat transfer characteristics of laminar swirl flow through a circular tube fitted with regularly spaced twisted-tape elements , 2001 .

[11]  Arthur E. Bergles,et al.  Swirl flow heat transfer and pressure drop with twisted-tape inserts , 2003 .

[12]  Sujoy Kumar Saha,et al.  Heat transfer and pressure drop characteristics of laminar flow in rectangular and square plain ducts and ducts with twisted-tape inserts , 2005 .

[13]  O. K. Sonju,et al.  The decay of a turbulent swirl in a pipe , 1965, Journal of Fluid Mechanics.

[14]  S. Saha,et al.  Numerical prediction of laminar flow and heat transfer characteristics in a tube fitted with regularly spaced twisted-tape elements , 1990 .

[15]  Robert E. Block,et al.  Investigation and characterization of pressure drop in evenly spaced twisted tapes , 2010 .

[16]  U. N. Gaitonde,et al.  Heat transfer and pressure drop characteristics of turbulent flow in a circular tube fitted with regularly spaced twisted-tape elements , 1990 .

[17]  A. Bergles,et al.  Critical Heat Flux and Pressure Drop of Subcooled Flow Boiling in Small-Diameter Tubes with Twisted-Tape Inserts , 1996 .

[18]  R. M. Manglik,et al.  Heat Transfer and Pressure Drop Correlations for Twisted-Tape Inserts in Isothermal Tubes: Part II—Transition and Turbulent Flows , 1993 .

[19]  A. Date,et al.  Development of correlations for predicting characteristics of laminar flow in a tube fitted with regularly spaced twisted-tape elements , 1990 .

[20]  O. Klepper.  HEAT TRANSFER PERFORMANCE OF SHORT TWISTED TAPES. , 1972 .